Investment in Securities (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss	$ 34,900		$ 34,900		$ 35,100
Available-for-sale securities Realizes Losses - Write offs	(2,700)	$ (1,000)	(8,400)	$ (2,500)
Catch-up premium amortization adjustment	(500)	$ 2,100	(1,000)	$ 1,500
Residential mortgage loans | Loans held-for-investment [Member]
Securities, Available-for-sale [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 22,600		$ 22,600		$ 23,700